1. Field of the invention
The invention concerns an instrument for artificial insemination, embryo transfer or sampling follicular liquids in mammals in general and in horses, pigs, sheep, goats, cattle, deer and all carnivores in particular.
2. Description of the prior art
There are known laparoscopy techniques for "in situ" manipulation of the genital tract and the ovaries using instruments manipulated from outside the animal but inserted into the abdominal cavity through the opening in a trocar previously inserted through the skin and the peritoneum. This technique is employed when the neck of the uterus is difficult to pierce, as in goats, or even impossible to pierce, as in sheep and dogs. It is preferred over surgical intervention (laparotomy) which usually causes as a post-operative complication adherence of the broad ligament and/or of the peritoneum to the oviduct and/or the uterus and/or endometrial adhesions.
The invention is therefore concerned with an instrument that can be used for artificial insemination or embryo transfer by a transperitoneal route, for example in goats, sheep and dogs, or by the natural path where the morphology of the mammal lends itself to this. This instrument may also be applied to sampling follicular liquids by the cervical route.
There are already known (French patent application No. 85 12 386 of Aug. 14, 1985) syringes formed by a sheath and a piston translational movement of which is accurately controlled by a thumbwheel carried by a sleeve coupled to the anterior end of the sheath. In this embodiment the anterior end of the sheath is extended by a needle coupled to a plug comprising a conical cavity, this plug being adhesively bonded or welded to the inside of the anterior end of the sheath. It is then possible to use either a piston provided with a removable sealing head or (where the sheath encloses a fine sterilized packaging straw) the plunger stem itself, the piston head being in this case removed and replaced by the "factory" plug usually closing off the packaging straw.
The sheath is protected externally by a rigid cover or tubular plug preventing it deforming when it is inserted.
One object of the invention consists in improvements to this known instrument so that it may be used, especially in the transperitoneal technique, under the best possible handling and dosage control conditions, whether for artificial insemination or for embryo transfer.
Another object of the invention is to free one hand of the operator so that he can manipulate simultaneously the transfer instrument and the endoscope.
A final object of the invention is to mask the needle during the insertion of the instrument to avoid bruising, injuring or stressing the animal.